Section 31(2)(d) in The M.P. Civil Services (Leave) Rules, 1977
(d)Twenty-four months where the leave is required for the purposes of prosecuting studies certified to be in the public interest, provided the Government servant concerned has completed three" years continuous service on the date of expiry of leave of the kind due and admissible under the rules [including three months extraordinary leave under sub-rule (2) (a) above] and executes bond in Form 5 to serve the State Government for a period of three years after return to duty failing which he would be required to pay a penalty of Rs. 1000 :